Looking for HEI super coil info for 1982 C3. Who has it? Is it a good idea? Does it need high voltage cap and rotor?

Unless you're planning on racing, the stock GM HEI coil is more than adequate for any street purpose. You can certainly buy some high performance direct drop-in coils...Summit Racing and Jegs sell them from any number of manufacturers, but you won't likely see any difference on the street unless you have a bad coil to start with.